Dual Inhibition of PI3K-AKT Signaling Pathway by miR-542 Overexpression in Cervical Cancer

The PI3K-AKT signaling pathway (SP) has been introduced as a key regulatory pathway in cervical cancer (CC). Inhibition of this SP could be a therapeutic strategy in CC. Our previous bioinformatics analysis exhibited that miR-542 could have a dual inhibitory function on this SP by targeting PIK3CB and AKT1 genes with its two arms (-3p and -5p) and proposed it as an appropriate therapeutic target for CC. The current study experimentally investigated the dual inhibitory function of miR-542 on the PI3K-AKT SP. qRT-PCR was performed following transfection of the recombinant pEGFP-C1 vector containing miR-542 precursor into the CaSki and miR-542 overexpression to quantify the expression level of target genes of miR-542 (AKT1 and PIK3CB) as regulators of PI3K-AKT SP and their downstream genes affecting cell proliferation and apoptosis (CDKN1A and BCL2). In addition, the effect of overexpression of miR-542 on cell cycle and apoptosis was examined by flow cytometry using propidium iodide and PE Annexin V/7-AAD staining, respectively. The recombinant cells showed a significant decrease in the expression of AKT1, PIK3CB, and BCL2 genes, and a significant increase in the level of CDKN1A gene expression, simultaneously with the highest overexpression of miR-542 at 48 h post-transfection. Furthermore, the apoptosis was remarkably induced and the cell cycle was arrested in recombinant cells compared to mock cells. miR-542 promoted apoptosis and cell cycle arrest by dual inhibiting the PI3K/AKT SP. It may be introduced as an appropriate target for CC treatment.